In situ and real time quality control in additive manufacturing process

Abstract

Use of a sensor read out system with at least one fiber optical sensor, which is connected via at least one signal line to a processing unit as part of an additive manufacturing setup, for in situ and real time quality control of a running additive manufacturing process. Acoustic emission is measured via the at least one fiber optical sensor in form of fibers with Bragg grating, fibre interferometer or Fabry-Perot structure, followed by a signal transfer and an analysis of the measured signals in the processing unit, estimation of the sintering or melting process quality due to correlation between sintering or melting quality and measured acoustic emission signals and subsequent adaption of ion and electron beams, microwave or laser sintering or melting parameters of a ion and electron beams, microwave or laser electronics of the additive manufacturing setup in real times via a feedback loop as a result of the measured acoustic emission signals after interpretation with an algorithmic framework in the processing unit.

The invention claimed is: 
     
       1. An additive manufacturing setup, comprising:
 a set of electronics comprising at least one of ion beam electronics, electron beam electronics, microwave electronics, or laser electronics; 
 one or more emission sources comprising at least an ion beam emission source, an electron beam emission source, a microwave emission source, or a laser emission source; 
 a focusing device for focusing emissions from the one or more emission sources on a process surface of a sintering or melting body in an emission irradiated focused spot with controllable emission parameters; and 
 an integrated sensor read out system comprising
 at least one optical fiber sensor arranged alongside a process axis between the one or more emission sources and the emission irradiated focused spot, wherein the at least one optical fiber sensor detects acoustic emissions generated by focusing the one or more emission sources on the process surface during a sintering or melting process, 
 at least one signal line between the at least one optical fiber sensor and a processing unit, wherein the at least one signal line transmits the detected acoustic emissions to the processing unit, and wherein the processing unit processes the acoustic emissions to determine sintering or melting adjustment parameters for a subsequent sintering or melting process, and 
 a feedback loop from the processing unit to the set of electronics for application of the sintering or melting adjustment parameters for subsequent sintering or melting process. 
 
 
     
     
       2. The additive manufacturing setup according to  claim 1 , wherein the at least one optical fiber sensor comprises fibers with at least one of Bragg grating, fiber interferometers, or Fabry-Perot structures. 
     
     
       3. The additive manufacturing setup according to  claim 1 , wherein the at least one fiber optical sensor comprises a multiplicity of fiber optical sensors surrounding the process axis symmetrically for measuring acoustic emission. 
     
     
       4. The additive manufacturing setup according to  claim 3 , wherein an axis of each fiber optical sensor of the multiplicity of optical fiber sensors is situated at an equal angle of range 0° to 90° relative to the process axis. 
     
     
       5. The additive manufacturing setup according to  claim 4 , wherein an axis of each fiber optical sensor of the multiplicity of optical fiber sensors is tilted in an angle between 10° and 70° between all optical fiber sensors and the process axis. 
     
     
       6. The additive manufacturing setup according to  claim 5 , further comprising:
 at least one photo detector connected to the processing unit, wherein the at least one photo detector collects optical emissions comprising at least one of a back reflection of heating irradiation, temperature, or other optical emissions within a melting or sintering, wherein the processing unit processes the optical emissions in addition to the acoustic emissions to determine the sintering or melting adjustment parameters.